Update Alpine version to 3.16
Update Alpine version to 3.16

It's the latest stable version.
https://www.alpinelinux.org/posts/Alpine-3.16.0-released.html

Change-Id: I567bf68675e8de853aeb204c97994b08f3dda6c2
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>
(cherry picked from commit 253e17d5b10965758465b08c7d13589c4ff7d0cf)

opnfv/functest,opnfv/functest